/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.table.delegation;

import org.apache.flink.annotation.Internal;
import org.apache.flink.table.api.internal.TableResultInternal;
import org.apache.flink.table.operations.Operation;

import java.util.Optional;

/**
 * An extended operation executor which provides method for executing operation. External pluggable
 * dialect can implement this interface to execute operation in its own way instead of using Flink's
 * own implementation for operation execution.
 */
@Internal
public interface ExtendedOperationExecutor {

    /**
     * Execute the given operation and return the execution result. This method will delegate
     * Flink's own operation execution.
     *
     * <p>If return Optional.empty(), the operation will then fall to Flink's operation execution.
     */
    Optional<TableResultInternal> executeOperation(Operation operation);
}
